=count(Fields!GMPI.Value) *900 for group column A gives the same total of $240,000 for all 3 groups, but =count(Fields!GMPI.Value) * 600 for group col B works corretly for each group having a different value.

any ideas, it is almost as if ssrs is glitching cuase the values in the field columns do not add up induvidually to 240,000.

Thanks so much. It was grouping them all by market, just that group header was choking. A fix that worked was doing the calculation at the data level in t-sql and not in the group header, although other columns were behaving fine with expressions in the group headers.